The invention concerns an electrodynamic drive train system for a vehicle.
Drive systems for vehicles customarily comprise an internal combustion motor as the driving machine, a subsequent transmission and a friction clutch placed between the internal combustion motor and the transmission or again, comprise a hydrodynamic converter placed between the internal combustion motor and the transmission. The friction clutch or the converter are burdened with losses and present energy losses in the drive train.
The invention has the purpose of minimizing the losses which occur between the driving machine and the transmission.
In accord with the invention, and with an electrodynamic drive system for a vehicle, it is proposed to place a planetary gear drive between a driving machine and a transmission, which said planetary gear drive encompasses the three elements, sun gear, internal gear, and planetary carrier. Of these three elements, a first element is connected to the transmission, a second element is bound to the driving machine, and a third element is coupled with at least one electric motor. An advantageous construction possesses a control, which can regulate the at least one electric motor in the 4-quadrant operation. A further embodiment possesses a clutch between two elements of the planetary drive for the lockup or bypass of the planetary drive, which in one type of assembly includes a dog clutch. In an additional arrangement, an overtake-free wheeling device is placed between the driving machine and the electrodynamic drive system. In yet another embodiment, several electric motors in combination act upon one of the elements of the planetary drive. In an advantageous embodiment, a lock-up torque converter is provided for the formation of torque support during the startup procedure. This can be carried out by the simultaneous engagement of two shifting stages in the transmission, by means of a parking lock, by a braking apparatus of the vehicle and a simultaneously engaged gear stage on an input shaft of the transmission. In one embodiment form, on one shaft of the planetary drive a brake retard is placed.
By means of the invented drive system, a more environmentally friendly functioning of the vehicle and a lowering of the operating life costs are attained. With the present invention, a drive system is presented, which avoids any friction based starting element. What otherwise would be power lost in slippage, can be now used as a additional power for the electrical on-board system. At the same time, use of the electric motor permits an increase of torque and the motor can be employed as a booster element in the concept of additional drive, during an accelerating period. After the startup phase, the electric motor can be converted to a generator for on-board current supply. The electric motor, in addition, can be employed as a source of power for electrically driven, ancillary power take offs. The use of the electric motor as a starter for the internal combustion motor and as a vehicle drive without the exhaust of environmentally unfriendly substances is a growing technology. At the same time, with corresponding control, as well as in connection with an additional retarding braking system, such as, for example, a hydrodynamic retarder, a damping of interruptions in the drive train can be achieved.
The planetary gear set proposed for the invented drive system can be inserted in front of an optional manual transmission. The following are connected to members of the planetary gear drive:
the input shaft from the internal combustion motor, if required, with overrunning clutch for start-stop operation or for the Zero-Emission-Vehicle-operation, that is, powering the vehicle by the electric motor, when the internal combustion motor is not turning,
at least one electric motor, which can operate both as a drive motor as well as a generator,
if required, a shifting clutch for bypassing the electric motor, when it need not be required as a motor,
as well as the output shaft to the manual transmission and
in some cases, a retarder.
In comparison to conventional drive systems, the following can be eliminated:
a dry clutch with disengagement means,
a starter,
a generator (light machine),
in some cases, mechanical auxiliary power take-offs,
partially, one or more mechanical gear stages, because the electrodynamic drive system introduces a corresponding increase of torque.